Duct anode



J.. P. OLIVER Ducmn ANODE March 3, 1959 Filed April 18, 1955 INVENTQR JOHN P. OLIVER ATTORNEY United States Patent '0 DUCT ANODE John P. Oliver, Berea, Ohio, assignor to Union Carbide Corporation, a corporation of New York Application April 18, 1955, Serial No. 501,779

1 Claim. (Cl. 204-196) This invention relates to spaced anodes adapted for use in ducts and elsewhere, that is, to anodes which are capable of being pulled into or through a duct or conduit. An object is to provide such an anode that is capable of being pulled into a duct with safety and convenience. Another object is to provide spaced anodes in which a continuous electricalconductor ofmetal extends entirely through each anode and is adapted to withstand any additional stress without transmitting such stress through the carbonaceous anode material.

The prior type of protective anodewas providedwith a short pigtail by means of which it was connected with a conductor for receiving electric current. Such a construction was not well suited for being pulled through a duct of nearly the size of an anode. According to this invention there is provided an anode and supply conductor of a type readily adapted to be pulled into and through a duct. i

More specifically a carbonaceous anode, preferably of graphite is in two halves. A conductor is cut it necessary where the anode is to be located. After severing the conductor each anode half portion is slipped over one of the cut ends and moved back from such end. The ends of the conductor are then electrically connected by some type of connector capable of transmitting substantial tension applied to the conductor. Such connector is provided with threads at its outer surface intermediate its ends. The anode halves are then moved onto and threaded over such connector with their adjacent ends abutting one another, or nearly so.

Referring to the drawings Fig. 1 is a longitudinal partial section of an anode and conductor made according to this invention.

Fig. 2 is a longitudinal view, partially in section of the connector and conductors of Fig. l with the anode removed.

Fig. 3 is a longitudinal section through a modified form of a connector but not having the anode in place.

Fig. 4 is a section on the line 4-4 of Fig. 5 and showing a further modified connector with no anode in po sition.

Fig. 5 is a transverse cross section through the connector of Fig. 4.

Fig. 6 shows a plurality of anodes connected by the conductor and spaced as desired.

In Fig. 1 the anode 10 comprises two half sections as illustrated each of which is threaded on an electrical and metallic connector 14 into which the bared ends of the conductors 11 are inserted. A slight space 12 between the ends of the conductors 11 is provided though not necessary, it being desirable that each end of the conductors 11 be inserted into the connector 14 a substantially similar amount so that the resistance between the connector and each conductor may be substantially the same.

Where the anode is to be located the conductor 11 provided with insulation 13 is cut and each of the severed ends is bared for a distance at least about half the length 2,876,190 Patented Mar. 3, 1959 of the connector 14. Over each of the severed ends an anode half portion 10 is slippedand pushed back far enough not to interfere with effecting the connection between the connector 14 and each of the ends of the conductor 11. The connector illustrated in Figs. 1 and 2 is of a well-known type commercially called a Burndy Crimpit or Hy-Splice. As illustrated the central portion of the connector is screw threaded at 16 leaving the end portions unthreaded. After insertion of the ends of the conductors 11 a tool is applied to crimp or press in localized portions of the-ends of the connector. Being of soft metal such as copper or other appropriate conductive alloy the crimping tool is able to press in portions and effect a slight distortion of the stranded conductor as shown at 17 in Fig. 2. This inventionis not limited to any particular type of connector since many kinds of I connectors are suitable, although it is preferable that the a screw threaded engagement between the inner surface of the anode sections and outer surface of the connector. When the ends 11 of the conductor have been inserted and connected as described the anode half portions are screwed onto the connector until they substantially abut one another as shown in Fig. 1. To provide a Waterproof filling within each anode half section between the connector, conductor and anode some appropriate plastic or cement is poured or forced into the anode through holes 23 and 24 shown in Fig. 1 provided for that purpose, until it exudes slightly out the ends of the anode sections and also out through the space 25 between anode half section's. Many types of waterproof plastic cements are appropriate, both the true thermoplastic and the thermosetting resinous plastics and other commercial waterproof types well known in the art. When an insulating plastic is used as the filler, the fit must be good to avoid the insulating material getting into the space between the threads and the anode to reduce the desirable electrical conductivity of the anode connection. A layer of cement or plastic is applied at the abutting ends of the anode section as shown at 25, suitably by application to the end to be abutted. The electrical resistance of the connector illustrated in Fig. 1 has been found to be as low as .0005 ohm between a conductor 11 and the graphite anode. A carbonaceous anode is preferred and has been found to possess a longer life than the usual metal anodes, but the use of such carbonaceous material as the anode is not considered new in this invention. Due to the higher electrical conductivity of graphite as compared with amorphous carbon, the graphite is preferred as the anode material.

The connector 18 shown in Fig. 3 is of a somewhat similar nature to that shown in Figs. 1 and 2. Its central portion is threaded at 16a for cooperation with a graphite anode not shown. Set screws 19 and 20 or a plurality of them in each end of the connector provide satisfactory connections between the conductor strands and the connector. As illustrated in Fig. 1 the anode half sections extend over at least part of the insulated portions 13a of the conductor.

In Figs. 4 and 5 is shown another embodiment of an appropriate connector which may be of lead or other soft metal crimped on the cable with a hand die to preserve the thread, the slot 22 being formed to enable the connector to be deformed slightly in clamping it on the conductor end 11b. As before the screw threads 16b are for the purpose of cooperating with the threads on the inside of the anode sections. Some well known type of waterproof cement is also preferably used to fill the inside of the anode and prevent access of water to the connector 21 and around the insulated portions 131; of the conductor within the anode.

lumnae Fig. 6 shows how a plurality of anode sections 10 may be sp aced apart whatever amount is desired or' found convenient, ;the spacing being dependent on the locations at which; the insulated; conductor 11- is cut. The, appear: ance ofcutportions of the. Conductor 11in Fig, 6 must not be. misleading'as this appearance is made to indicate portions, of the conductor being, broken away, as the drawing. is not large enough toshow the anode sections with the customary spacing, between them. It will be understood that the cut, portions of the conductor 11 are within each anode and approximately adjacent the contiguousends of the. anode half sections.

An advantage of this invention resides in the provision ofananode construction inwhich the anodes may be spaced apart. whatever amount is desired and the cut portions. of the conductor. are electrically, connected to be capable of. withstanding. tensional stress incident to. pulling the'anod'es through a duct or conduit without having any of.,such. tensional' stress borne by a carbonaceous anode, The principal stress to which the, anode is. subjectedis a slight compression due to friction between the outer surface of the anode and an inner surface of' a duct. The provision of tensional stress in the conductor cement has been found to he the preferred waterproof type of filling. v The use of the crimped ends. on the connector shown in Figs, land 2 or the set screws shown in. Fig, 3 provide a, satisfactory low, resistancebetween the connector and each of the hated conductor ends without,v having to solder any of the joints, though, of

course,, when. desired, solder. is notiprecludedl Another place .where the construction. of the presentinvention has,

been found desirableis around the hulls of metal ships,

the supporting conductor 11 there serving to support the anodes and hold them in thedesired spaced operating" condition as well as provide a supply conductor for cur rent which is to be dissipated from the anodes. In brief, this duct anode and its connection is useful outside of a pipe or duct where anodes have heretofore been used.

I claim:

A structure adapted to use in a cathode protective system which structure comprises a plurality of series disposed conductor cables, each pair of adjacent conductor cable ends having an electrically conductive connector for electrically uniting said cable ends and physically connectin'gsaidcahle ends to transmit tensile forces; therealong, a pair of elongated electrodes of impervious carbon and adapted to provide an anode in said system, said electrodes being threadedly secured about said connector and overlying said connector and said cable ends,

. said, electrodes being disposed With their inner ends in adjacency with each other and adapted to axially rejceive through the outer ends thereof the respective cable ends, and water sealing means between said inner electrode ends, whereby tensile forces through said' structure are borne by said cable ends and said connector.

References Cited in the file of thispatent UNITED STATES PATENTS 

